Apparatus for continuous casting of rod and other strand material



Aug-29,1957 F.HARDERS ETAL APPARATUS FOR CONTINUOUS CASTING OF ROD AND OTHER STRAND MATERIAL Filed May 6, 1964 APPARATUS FOR CONTINUOUS CASTING OF ROD AND OTHER STRAND MATERIAL Fritz Harders, Post Ergste uber Schwerte (Ruhr), and

Rudolf Vonnemann, Dortmund-Wellinghofen, Germany, assignors to Dortmund-Hinder Hiittenunion Aktiengesellschaft, Dortmund, Germany, a corporation of Germany Filed May 6, 1964, Ser. No. 365,309

Claims priority, application Germany, May 8, 1963,

6 Claims. (Cl. 164-281) Our invention relates to the production of intermediate or semi-finished products of rod or other strand shape, such as round, square or otherwise profiled stock for wire, screw, shaft or rail production and the like, and in a more particular aspect to the production of such ingot or stock materials by continuous casting.

According to the continuous casting method, metal in molten condition is continuously supplied to a mold from one end thereof. The mold encloses a space of prismatic or cylindrical shape whose opposite end is open. The material continuously issues from the open end as a solidified product whose cross section corresponds to that of the casting mold. Our invention is based on the same casting principle.

It is an object of the invention to improve the continuous casting of rod and other strand material in various respects. One of the more specific objects is to produce a material of an improved, more densified structure. Another object is to produce a product which exhibits a minimized amount of impurities, such as occluded oxides, slag and other contaminations.

Still another object of the invention is to provide an apparatus from which the material being cast will continuously issue in a horizontal direction so that it can be passed to further fabrication without necessitating a reversal in direction or a subdivision by cutting. Another, more specific object akin to the one last mentioned is to provide a continuous casting apparatus that affords issuing a rod material of infinite length suitable to be directly passed into a rolling mill.

The foregoing and further objects and advantages of the invention as well as its essential features, these features being set forth with particularity in the claims annexed hereto, will be apparent from the following description of an embodiment of a continuous casting machine according to the invention illustrated by way of example on the accompanying drawing in which:

FIG. 1 is a partly sectional side view of the machine in schematic representation, and

FIG. 2 is a cross section taken along the line 22 in FIG. 1.

Mounted on a foundation 1 is a horizontally displaceable slider 2 which is joined with a rack 3 meshing with pinion 4 on the shaft 5 of a motor 6 operable in one or the other direction for shifting the slider 2 to one or the other side.

The slider 2 carries four legs 8 of a frame structure 7, only two legs being visible on the drawing. Each leg is formed by a hydraulic cylinder 9 with a piston rod 10 which is vertically displaceable in the cylinder. By supplying or draining oil from each cylinder, the pistons can be moved upwardly or downwardly for changing the height of the frame structure 7.

' United States Patent 0 19 of the frame structure 7. By means of the motor 18, a relatively rapid rotation can be imparted to the shaft 13 and thus to the top flange 14.

The flange 14 carries a coaxial drum generally denoted by 20. The drum has a bottom wall 21, a top wall 22 and a circularly cylindrical jacket 23. The bottom Wall 21 is firmly joined with the flange 14. The top wall 22 has a central circular opening 24. Top, bottom and peripheral jacket of drum 20 consist of sheet steel and are internally lined with refractory material 24 which covers the entire inner wall surface and has an opening 26 registering with the opening 24.

Provided above the drum 20 are means for suspending a casting ladle generally denoted by 27. The ladlesuspension means comprise a support 28 on which a slider 29 is horizontally displaceable. The ladle 27 has a shape -as conventional in steel mills and consists of an outer steel shell and an inner refractory lining 31. The bottom of the ladle has an opening 32 which can be closed by a conventional plug 33. A bracket 34 on each side of the ladle is mounted on the slider 29 and carries in its upper end a pivot for the ladle. The ladle 27, thus supported on the slider 29, can be moved into and out of the illustrated position by correspondingly shifting the slider.

Attached to a bottom plate 35 of the ladle 27 and in alignment with the bottom opening 32 is an outlet pipe 36. This pipe can be cooled with water and for this purpose has a double wall indicated at 37. Two nipples or stub pipes 38 and 39 serve for passing the water through the jacket space of pipe 36. Starting from opening 32,

, the pipe 36 extends vertically downward. At some distance below the ladle, the pipe 36 is bent laterally so as to form a horizontal portion 40 (FIG. 2). The lower end of the pipe is curved about 90 away from portion 40 in the same horizontal plane and forms another, likewise horizontal portion 41 of very short length (FIG. 2).

Located beside the drum 20 is a foundation structure 42 with guide means 43 for a slider 44 which can be horizontally displaced on foundation 42 in two coordinate directions, namely in the plane of illustration and per pendicularly thereto. The slider 44 carries a chamber structure denoted as a whole by 45. The design or shape of the chamber structure 45 generally resembles that of the casting molds'or ingot molds heretofore employed in continuous stock-casting processes, except that the longitudinal axis of the chamber 45 extends horizontally. The cross-sectional shape of the chamber 45 corresponds to that of the elongated rod or other product to be cast. Consequently, the, space formed by the chamber may be prismatic or cylindrical. When the cross section of the product is to be of circular shape, the chamber space has the shape of a circular cylinder. The wall of chamber 45 is cooled with water and forms a jacket space 46 which communicates with inlet and outlet ducts 47 and 48 for the supply and discharge of the coolant water.

The left side of the chamber 45 is closed by a rear wall 49. The right or front end 50 is continuously open. The rear wall 49 has an opening 51 connected with a material supply pipe 52. This pipe is also water cooled and for this purpose has a double wall indicaed at 53, as well as nipples 54 and 55 for the supply and discharge of coolant water. The shape of pipe 52 is similar to that of The top portion 11 of the frame structure 7 carries a bearing 12 for a vertical shaft 13 which is provided above the frame portion 11 with a flange 14 and below the pipe 36, that is, the horizontal portion of pipe 52 adjacent to the chamber 45, is followed by a vertical portion 57 extending downwardly through the openings 24 and 26 into the drum 20. The vertical portion 57 is continued by a horizontal portion 58 (FIGS. 1, 2) whose end curves laterally away to form still another horizontal but short portion 59 in the same horizontal plane (FIG. 2). By virtue of this particular shape, the tube 52 is located in the interior of the drum 20 in the particular manner apparent from FIGS. 1 and 2. The opening 60 of tube 52 is located in eccentric relation to the axis of drum 20 and below the top wall 22. The direction of the opening 60 is tangential to a circular cylinder whose axis coincides with the axis of the drum 20. The radial distance of opening 60 from the axis of drum 20 can be changed by displacing the slider 44.

The above-described device is operated as follows:

A ladle 27 according to FIG. 1 is filled with molten steel 61 and is placed upon the slider 29 with the aid of a crane. The tube 36 then passes through the opening 24 into the interior of the drum 20. The ladle 27 is then slightly moved toward the left by correspondingly shifting the supporting slider 29, so that the opening 62 of pipe 36 is situated beneath the top wall 22 of drum 20. The opening 62 then extends tangentially to a circular cylinder whose axis coincides with the axis of the drum 20, in this respect corresponding to the positioning of the opening 60 of tube 62. The adjustment now is the one shown in FIG. 2.

Then the drum 20 is placed in rotation by means of the motor 18 in the direction of the arrow b shown in FIG. 2. This direction is opposed to that of the tube openings 60 and 62. The pipes 36 and 52 as well as the casting chamber 45 are supplied with coolant water. Thereafter the plug 43 is pulled out of the ladle outlet opening so that the melt 61 drains through the opening 32 and the pipe 36 into the rotating drum 20.

The melt issuing from opening 62 flows onto the bottom of drum 20 and is then flung outward by centrifugal force toward the drum periphery. Consequently there is formed a ring-shaped body 63 consisting of liquid steel and having a radial thickness which increases with the further supply of molten steel from the ladle 27. As a result, the opening 60 of tube 52 passes into the ringshaped body 63. Since this opening is opposed to the direction of rotation b, some of the molten steel enters into the pipe 52 and is pressed through this pipe into the chamber 45. As the thickness of the ring-shaped body 63 increases, the opening 62 of the tube 36 also becomes immersed in the rotating melt. Since the opening 62 is likewise directed in opposition to the rotational direction b, there occurs a back pressure which tends to prevent the further drainage of molten steel 61 from the ladle. This results in an equilibrium condition. Consequently, even if no molten material is withdrawn through the pipe 52, the maximal thickness of the rotating ring 63 is limited by the back pressure at opening 62 reaching an equilibrium with the gravity of the molten material. For that reason the drum can never overflow, and the quantity of steel being replenished from the ladle 27 is accurately controlled in accordance with the quantity which is being withdrawn from the rotating ring body 63 through the tube 52.

Due to the centrifugal force produced in the rotating drum, the molten material is forced into the chamber 45 under a considerable amount of pressure. The temperature of the melt becomes reduced at the intensively cooled wall of this chamber so that the molten material solidifies. As in the known continuous casting of strand material, there occurs between a still liquid region 64 and an already solidified region 65 a boundary whose shape approximates that of a paraboloid. An already solidified rod or strand body 66 thus issues from the front opening 50 of the chamber 45 and can be supported by roller pairs 67 and 68 in the conventional manner.

The acceleration due to centrifugal force in the rotating drum 20 is considerably larger than the acceleration due to gravity. This has the effect that any impurities contained in the melt 61 and having a lower specific gravity than the molten metal, are floated to the surface with a particularly good effectiveness. Hence such impurities are rapidly transported to those localities of the ring-shaped body 63 that have the smallest distance from the drum axis. The molten material entering into the opening 60 thus exhibits a considerably higher degree of purity than the melt entering into the casting mold of the conventional continuous casting devices.

With the known continuous casting of rod stock, the melt enters into the vertically upright casting mold only by gravity. According to the invention, however, the melt entering into the chamber 45 is subjected to the high pressure produced by centrifugal force. This pressure can be made as high as desired, simply by correspondingly selecting the rotating speed of the motor 18. Under the effect of the high pressure, the resulting product 66 possesses a structure which is considerably denser and therefore better than the structure obtainable with the continuous stockcasting method heretofore known.

As mentioned, the known casting processes rely on gravity for filling the molds so that these must be arranged vertically. Consequently, the resulting elongated product issues in a vertical direction which requires cutting it into relatively short pieces or guiding it by relatively complicated direction-changing means so that it will travel on a generally horizontal path. The latter expedient, however, is applicable only with relatively thin stock material. In contrast thereto, the invention affords the possibility of operating with a horizontal casting chamber 45 from which the strand product 46 issues already in a horizontal direction. The product, therefore, need not necessarily be cut into shorter pieces but, in principle, can be given any desired or infinite length. This oflers the possibility, for example, to guide the resulting strand product without interruption directly into a rolling mill.

While the invention has been described with reference to the processing of steel, it is obvious that it is readily applicable to other metals.

To those skilled in the art it will be obvious from a study of this disclosure that the invention affords of various modifications and can be given embodiments other than particularly illustrated and described herein, without departing from the essential features of the invention and within the scope of the claims annexed hereto.

We claim:

1. Apparatus for producing intermediate products in elongated rod or strand shape comprising:

(a) a rotatable drum having a vertical axis and having a top wall with an opening;

(b) a first pipe protruding downwardly through said opening into the interior of said drum and having in said drum an outlet opening portion radially spaced from the drum axis and extending substantially in a direction tangential to an imaginary cylinder having an axis coincident with said drum axis;

(c) means for feeding molten metal into said first pipe;

(d) a second pipe protruding from above through said top-wall opening of said drum to below said top wall and having in said drum an inlet opening portion extenting substantially in a direction tangential to an imaginary cylinder having an axis coincident with the axis of said drum which is directed in the same sense, relative to said drum axis, as said outlet opening portion of said first pipe;

(e) means for driving said drum in a sense directed toward the inlet opening end of said second pipe;

(f) a casting chamber having an open front end for issuing a solidified casting, said second tube being connected to the opposite end of said chamber for supplying it with molten metal from said drum under pressure due to centrifugal force produced by rotation of said drum; and

(g) means for cooling said casting chamber and means for guiding the solidified casting issuing from the open end of said casting chamber.

2. In a continuous casting apparatus according to claim 1, said casting chamber having a horizontal axis so that the casting issues in a horizontal direction.

3. Continuous casting apparatus according to claim 1, comprising means for changing the radial distance be- References Cited UNITED STATES PATENTS DeRomilly 103-401 X Gurley 103101 Kuhn 74-45 Mattson 2257.2 X Armand et a1. 22-57.2

I. SPENCER OVERHOLSER, Primary Examiner.

10 R. S. ANNEAR, Assistant Examiner. 

1. APPARATUS FOR PRODUCING INTERMEDIATE PRODUCTS IN ELONGATED ROD OR STRAND SHAPE COMPRISING: (A) A ROTATABLE DRUM HAVING A VERTICAL AXIS AND HAVING A TOP WALL WITH AN OPENING; (B) A FIRST PIPE PROTRUDING DOWNWARDLY THROUGH SAID OPENING INTO THE INTERIOR OF SAID DRUM AND HAVING AN SAID DRUM AN OUTLET OPENING PORTION RADIALLY SPACED FROM THE DRUM AXIS AND EXTENDING SUBSTANTIALLY IN A DIRECTION TANGENTIAL TO AN IMAGINARY CYLINDER HAVING AN AXIS COINCIDENT WITH SAID DRUM AXIS; (C) MEANS FOR FEEDING MOLTEN METAL INTO SAID FIRST PIPE; (D) A SECOND PIPE PROTRUDING FROM ABOVE THROUGH SAID TOP-WALL OPENING OF SAID DRUM TO BELOW SAID TOP WALL AND HAVING IN SAID DRUM AN INLET OPENING PORTION EXTENTING SUBSTANTIALLY IN A DIRECTION TANGENTIAL TO AN IMAGINARY CYLINDER HAVING AN AXIS COINCIDENT WITH THE AXIS OF SAID DRUM WHIH IS DIRECTED IN THE SAME SENSE, RELATIVE TO SAID DRUM AXIS, AS SAID OUTLET OPENING PORTION OF SAID FIRST PIPE; 